The Blueskin Resilient Communities Trust says guy wires securing the pole were cut with something like a bolt-cutter in what it says was the work of an ''extremist''.
The trust says it will hamper work to collect data needed for a coming court case.
The equipment was insured.
Last year the trust was denied consent for the wind farm on Porteous Hill.
The trust has said it hoped the $5million-$6million project would return $100,000 a year in profits for community needs and causes, and form a response to wider issues of climate change.
But the proposal drew the ire of nearby neighbours, who said property prices, quality of life and health would be negatively affected by the wind farm.
In August, the trust appealed the decision, and an Environment Court hearing is set down for June 26.
Blueskin Energy project manager Scott Willis said it was discovered on Monday data had been lost from the tower.
Yesterday, a maintenance check was done, and it was discovered the problem was ''an act of criminal damage and vandalism''.
The tower had been fitted with sensitive instruments, including wind vanes, anemometers to record wind speed and solar panels to provide power.
It appeared the cups of the anemometers had been shot at before the pole came down.
The equipment, which has been in place since 2013, was severely damaged ''as you would imagine when it falls from a height''.
The pole had four guy wires at each of three levels, meaning some effort had been put in.
''The really sad thing is it was community donations that helped put the tower up, and pay for the instruments in the first place.''
Mr Willis said most people in Blueskin Bay wanted clean and green energy, but there was ''always an extremist around''.
The Environment Court had requested the trust do background acoustic monitoring, work the equipment was being used for.
The vandalism would have ''some impact'' on the noise assessment, but it was unclear how critical that would be.
''It does make it more complicated.''
Mr Willis said he had lodged a complaint with police.
''I think it's another hiccup in a project that's going to ultimately benefit our community.
''You can't do much when you've got an extremist or two in a community.
''You'll always have that, and you'll always have a hot-head.''
Asked if he had thoughts on why the damage had occurred now, he said someone might want to derail the collection of data for the court process.
''It just doesn't seem to make a lot of sense that someone doesn't want to follow the legal path.''
